diff options
| author | Jonathan Austin <Jonathan.Austin@arm.com> | 2012-09-21 18:51:44 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-09-26 22:57:52 +0100 |
| commit | 56942fec06efa0e17df0f4c3b438332c923b9014 (patch) | |
| tree | 89b604c987b7f6a0eaaa16af7a9d8f45711349a7 /arch/arm/kernel/arch_timer.c | |
| parent | a1b2dde70419ae947fd7c9c8fcad7da005dc600e (diff) | |
| download | lwn-56942fec06efa0e17df0f4c3b438332c923b9014.tar.gz lwn-56942fec06efa0e17df0f4c3b438332c923b9014.zip | |
ARM: 7538/1: delay: add registration mechanism for delay timer sources
The current timer-based delay loop relies on the architected timer to
initiate the switch away from the polling-based implementation. This is
unfortunate for platforms without the architected timers but with a
suitable delay source (that is, constant frequency, always powered-up
and ticking as long as the CPUs are online).
This patch introduces a registration mechanism for the delay timer
(which provides an unconditional read_current_timer implementation) and
updates the architected timer code to use the new interface.
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Jonathan Austin <jonathan.austin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/arch_timer.c')
| -rw-r--r-- | arch/arm/kernel/arch_timer.c | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index c04c2a6da470..c8ef20747ee7 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -21,6 +21,7 @@ #include <linux/io.h> #include <asm/cputype.h> +#include <asm/delay.h> #include <asm/localtimer.h> #include <asm/arch_timer.h> #include <asm/system_info.h> @@ -39,8 +40,7 @@ enum ppi_nr { static int arch_timer_ppi[MAX_TIMER_PPI]; static struct clock_event_device __percpu **arch_timer_evt; - -extern void init_current_timer_delay(unsigned long freq); +static struct delay_timer arch_delay_timer; static bool arch_timer_use_virtual = true; @@ -325,12 +325,9 @@ static cycle_t arch_counter_read(struct clocksource *cs) return arch_counter_get_cntpct(); } -int read_current_timer(unsigned long *timer_val) +static unsigned long arch_timer_read_current_timer(void) { - if (!arch_timer_rate) - return -ENXIO; - *timer_val = arch_counter_get_cntpct(); - return 0; + return arch_counter_get_cntpct(); } static cycle_t arch_counter_read_cc(const struct cyclecounter *cc) @@ -441,11 +438,13 @@ static int __init arch_timer_register(void) arch_timer_global_evt.cpumask = cpumask_of(0); err = arch_timer_setup(&arch_timer_global_evt); } - if (err) goto out_free_irq; - init_current_timer_delay(arch_timer_rate); + /* Use the architected timer for the delay loop. */ + arch_delay_timer.read_current_timer = &arch_timer_read_current_timer; + arch_delay_timer.freq = arch_timer_rate; + register_current_timer_delay(&arch_delay_timer); return 0; out_free_irq: |